The tails of Alaska and Hawaiian airlines aircraft as seen at Oakland International Airport in 2011. / Ben Mutzabaugh, USA TODAY

by John Bacon, USA TODAY

by John Bacon, USA TODAY

The FBI is calling it a "miracle" and the airline says a teen who hopped the fence at a San Jose airport is "lucky to have survived" a 5-hour flight to Maui - in the wheel well of a Boeing 767.

The 15-year-old stowaway survived freezing temperatures that might have reached minus-80 degrees outside the plane and the thin air available at 38,000 feet, FBI spokesman Tom Simon said.

"I understand everybody's skepticism but his story checks out," Simon told USA TODAY. "He went into the wheel well in California and he came out of the wheel well in Hawaii."

Security video indicated the teen was able to breach San Jose's Mineta International Airport security on Sunday and climb undetected into the wheel well of Hawaiian Airlines Flight 45.

Howard Mell, a Cleveland area emergency physician who is a spokesman for the American College of Emergency Physicians, tried to put together a case for survival: If the temperature didn't dip quite so low in the wheel well, maybe he doesn't freeze to death. The very low oxygen at the altitude is harder to explain, he said.

"I'm not saying he couldn't have done it because apparently he could," Mell said, citing the before-and-after videos. But, he said, "from the standpoint of science, this is a very lucky child. â?¦ It would be extremely ill advised for anyone to try to duplicate his feat."

The FAA says it has been done before. Its data cite two cases of high-altitude flight by stowaways, one from Cuba to Spain and another from Colombia to Miami. The flights reached about 35,000 feet with outdoor temps as low as -65 degrees.

"The presence of warm hydraulic lines in the wheel-well and the initially warm tires provided significant heat," the FAA report says. Then, the slow climb to higher altitudes leads to gradual, but not fatal, unconsciousness and low body temperatures. Those gradually resolve as the plane slowly descends.

Upon landing, "individuals were found in a semi-conscious state, and, upon treatment, recovered," the report said.

The FAA report, however, notes that numerous "copycat" attempts have ended in death. There were 95 attempted stowaways on 84 flights worldwide between 1996 and August 2012, the FAA says. More than 75% resulted in deaths.

The latest stowaway rekindled debate about perimeter security at airports. Jeffrey Price, an aviation-security expert and associate professor at Metropolitan State University in Denver, said the security threat from airport intrusions hasn't reached a level demanding electrified fences or 24-hour surveillance of miles of perimeter.

"It's a cost-benefit analysis," Price said. "Right now the threat level isn't at the point where it justifies the cost."

Airports determine their perimeter security in coordination with the Transportation Security Administration, typically with fences or bodies of water such as at JFK, Boston's Logan or San Francisco's airport. Airport workers are trained to confront anyone in secure areas who isn't wearing a security badge, and police and civilians patrol the grounds.

But Price said regulations could be tightened if more stowaways emerged - or if someone brought explosives near a plane.

"The harsh reality is if that would have happened, you'd see more regulations on perimeter security," Price said.

Simon said the California teen ran away from his family and to the airport after an argument. The teen apparently slept through the flight, woke up about an hour after it landed in Maui and then jumped onto the tarmac.

Simon said the boy, who is not being identified, appeared to be unharmed and was released to child protective services. Police in San Jose said they are weighing charges against the youth, but he won't face federal charges in Hawaii, Simon said.

"Our issue was simple: Was he a threat to civil aviation," Simon said. "Once we found out he was a crazy kid with a bad idea, we moved on."

Authorities agree the youth defied all odds.

"Our primary concern now is for the well-being of the boy, who is exceptionally lucky to have survived," Hawaiian Airlines spokeswoman Alison Croyle said in a statement.

"This was a happy ending for everybody," Simon said. "It's a miracle."